The present invention relates to measuring tapes, and more particularly, to a reversible measuring tape that can be operated manually as well as automatically.
When measuring the length of an object or the distance between two points, a measuring tape may be used. A conventional measuring tape is operated manually. For measuring a long distance beyond the reach of the hands, it requires two persons to operate the measuring tape in measuring the distance. In order to eliminate this drawback, reversible measuring tapes are developed. However, regular reversible measuring tapes can only automatically rewind the tape, they cannot be controlled to automatically extend out the tape.
The invention has been accomplished to provide a manual/auto dual-mode reversible measuring tape, which eliminates the aforesaid drawbacks. It is one object of the present invention to provide a manual/auto dual-mode reversible measuring tape, which can be controlled to automatically extend out the tape to measure a distance. It is another object of the present invention to provide a manual/auto dual-mode reversible measuring tape, which provides a manual mode and an auto mode for selection. To achieve these and other objects of the present invention, a manual/auto dual-mode reversible measuring tape is provided comprised of a tape marked with marks for measuring, the tape having a longitudinal series of tooth holes, a shaft coupled to the housing of the measuring tape by a slip joint, a gear fixedly mounted on the shaft and adapted to mesh with the tooth holes of the tape, a reversible direct current motor connected to a direct current power source and adapted to rotate the gear in moving the tape in and out of the housing of the measuring tape, a manual/auto control switch controlled to move the shaft between a first position where the gear is forced into engagement with the tooth holes of the tape for enabling the tape to be automatically moved in and out of the housing of the measuring tape upon rotation of the reversible direct current motor, and a second position where the gear is disengaged from the tooth holes of the tape for enabling the tape to be moved in and out of the housing of the measuring tape by hand, and switch means, which controls the connection of the direct current power source to the reversible direct current motor and direction of rotation of the reversible direct current motor.